In recent years, the home-delivery pizza business has grown to immense proportions. From a business composed primarily of individual operators supplying pizzas in their neighborhoods, the marketplace has evolved into one where several large companies with operations across the United States prepare and deliver pizzas under a single trademark. The best known example of this is probably Domino's Pizza.
An important factor in the success or failure of home delivery pizza operations is the ability (or inability) to deliver piping hot pizzas. A desirable temperature for pizza at the time of delivery is 140.degree. F. or higher. The better the operator is able to maintain a high delivery temperature, the more successful the business becomes.
A variety of containers have been employed for carrying hot pizzas on delivery routes. The simplest are merely insulated bags in which the boxed pizzas are placed. More recently, containers with heating elements in them have also been used.